MEMORYSTATUS structure (winbase.h)

Contains information about the current state of both physical and virtual memory. The GlobalMemoryStatus function stores information in a MEMORYSTATUS structure.

Syntax

typedef struct _MEMORYSTATUS {
  DWORD  dwLength;
  DWORD  dwMemoryLoad;
  SIZE_T dwTotalPhys;
  SIZE_T dwAvailPhys;
  SIZE_T dwTotalPageFile;
  SIZE_T dwAvailPageFile;
  SIZE_T dwTotalVirtual;
  SIZE_T dwAvailVirtual;
} MEMORYSTATUS, *LPMEMORYSTATUS;

Members

dwLength

The size of the MEMORYSTATUS data structure, in bytes. You do not need to set this member before calling the GlobalMemoryStatus function; the function sets it.

dwMemoryLoad

A number between 0 and 100 that specifies the approximate percentage of physical memory that is in use (0 indicates no memory use and 100 indicates full memory use).

dwTotalPhys

The amount of actual physical memory, in bytes.

dwAvailPhys

The amount of physical memory currently available, in bytes. This is the amount of physical memory that can be immediately reused without having to write its contents to disk first. It is the sum of the size of the standby, free, and zero lists.

dwTotalPageFile

The current size of the committed memory limit, in bytes. This is physical memory plus the size of the page file, minus a small overhead.

dwAvailPageFile

The maximum amount of memory the current process can commit, in bytes. This value should be smaller than the system-wide available commit. To calculate this value, call GetPerformanceInfo and subtract the value of CommitTotal from CommitLimit.

dwTotalVirtual

The size of the user-mode portion of the virtual address space of the calling process, in bytes. This value depends on the type of process, the type of processor, and the configuration of the operating system. For example, this value is approximately 2 GB for most 32-bit processes on an x86 processor and approximately 3 GB for 32-bit processes that are large address aware running on a system with 4 GT RAM Tuning enabled.

dwAvailVirtual

The amount of unreserved and uncommitted memory currently in the user-mode portion of the virtual address space of the calling process, in bytes.

Remarks

MEMORYSTATUS reflects the state of memory at the time of the call. It also reflects the size of the paging file at that time. The operating system can enlarge the paging file up to the maximum size set by the administrator.

On computers with more than 4 GB of memory, the MEMORYSTATUS structure can return incorrect information, reporting a value of –1 to indicate an overflow. If your application is at risk for this behavior, use the GlobalMemoryStatusEx function instead of the GlobalMemoryStatus function.

Examples

For an example, see the GlobalMemoryStatus function.

Requirements

See also

GlobalMemoryStatus

GlobalMemoryStatusEx

Memory Performance Information